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| United States Patent |
5,178,891
|
|
Morikawa
, et al.
|
January 12, 1993
|
Method for stretching dough
Abstract
A method and apparatus is disclosed for stretching and thinning dough. This
apparatus consists of a plurality of conveyors 2,3, which are disposed in
series so that the traveling speed of the downstream conveyor 3 is higher
than that of the upstream conveyor 2, a roller 5 that reciprocates over a
given distance 1.sub.2 transverse to the traveling direction of the dough,
while reciprocating over a given distance 1.sub.1 in the traveling
direction, and a roller 4 that reciprocates over a given distance 1.sub.1
in the traveling direction in synchronism with the transverse roller. The
number of reciprocating strokes and the speed of both rollers are
regulated to obtain a sheet of high quality dough with a uniform texture.
| Inventors:
|
Morikawa; Michio (Utsunomiya, JP);
Hayashi; Torahiko (Utsunomiya, JP)
|
| Assignee:
|
Rheon Automatic Machinery Co., Ltd. (Utsunomiya, JP)
|
| Appl. No.:
|
761539 |
| Filed:
|
September 17, 1991 |
Foreign Application Priority Data
| Current U.S. Class: |
426/502; 426/517 |
| Intern'l Class: |
A21D 008/00 |
| Field of Search: |
426/496,502,512,517
425/335,363,373
|
References Cited
U.S. Patent Documents
| 2735379 | Feb., 1956 | Stiles | 426/502.
|
| 3894828 | Jul., 1975 | Moline et al. | 425/335.
|
| 4692110 | Sep., 1987 | Hayashi | 425/373.
|
| 4904491 | Feb., 1990 | Morikawa et al. | 426/502.
|
| Foreign Patent Documents |
| 309005 | Mar., 1989 | EP.
| |
| 326404 | Aug., 1989 | EP.
| |
| 386988 | Sep., 1990 | EP.
| |
| 410818 | Jan., 1991 | EP.
| |
Primary Examiner: Yeung; George
Attorney, Agent or Firm: Shoup; Guy W., Bever; Patrick T.
Claims
We claim:
1. A method of stretching dough comprising:
transporting the dough in a traveling direction;
rolling a pressure roller on a surface of the dough in a direction lateral
to the traveling direction of the dough, while reciprocating the roller in
the traveling direction.
2. A method of stretching a continuous mass of dough being conveyed on at
least one conveyor, the at least one conveyor transporting the dough in a
traveling direction, comprising:
rolling a first pressure roller on a surface of the dough in a direction
parallel to the traveling direction, while reciprocating the first roller
in the traveling direction, and
rollingly reciprocating a second pressure roller on the surface of the
dough in a direction lateral to the traveling direction of the dough,
while reciprocating the second roller in the traveling direction.
Description
FIELD OF THE INVENTION
This invention relates to the stretching of bread or cake dough. More
particularly, it relates to a method and apparatus whereby dough can
always be stretched and formed in a condition of uniform quality without
its inner texture being destroyed.
PRIOR ART
A prior art apparatus has been disclosed in U.S. Pat. No. 4,692,110 owned
by the assignee of the present application. In it a plurality of conveyors
that are driven at different speeds are arranged in series, and rollers
are disposed thereabove to freely rotate and to reciprocate in the
traveling direction of the conveyors, so that the dough placed thereon is
stretched to produce a dough sheet of a uniform thickness.
This prior art technique is effective in stretching and thinning dough
while it passes between the conveyors and rollers and is being compressed
by means of the rollers. However, if flour dough is stretched, it has only
a limited effect; namely, the stretching effect is limited to the
traveling direction of the conveyor.
This is because the protein of the dough stretched in that direction
hardens as it is stretched, thereby substantially preventing any
stretching in other directions.
SUMMARY OF THE INVENTION
This invention aims to enhance the stretching effect by simultaneously
stretching the dough in a direction transverse to the traveling direction
of the conveyor.
It is an object of this invention to provide an effective method of
stretching dough into a thin sheet of a uniform thickness.
It is another object of this invention to provide a method for
simultaneously stretching dough in the longitudinal and lateral
directions.
It is a further object of this invention to provide an apparatus having a
roller that reciprocates in the transverse and longitudinal directions so
that the dough can be stretched in more than one direction.
In one aspect of this invention, a method of stretching dough is provided
whereby the method consists of reciprocating a roller in both the
transverse and longitudinal directions such that the roller stretches the
dough being conveyed on a conveyor in more than one direction, to obtain
an improved stretching effect.
In another aspect of this invention an apparatus for stretching dough is
provided wherein a first roller, with its axis aligned parallel to the
traveling direction of a conveyor, is such that it reciprocates over a
given distance in a direction lateral to the traveling direction of a
conveyor while reciprocating over a given distance in the traveling
direction, and wherein a second roller disposed downstream of the first
roller, with its axis positioned ataright angle to the traveling
direction, is arranged to reciprocate over a given distance in synchronism
with the first roller. The rollers are simultaneously reciprocated over a
given distance in the traveling direction and over a given distance
transverse direction, to stretch the dough. The speed of the movement of
each of these rollers in each direction can be adjusted, thereby the locus
of the rolling of the rollers can be freely changed.
The selection of the locus of the rolling movements enables the apparatus
to stretch the dough in various directions so that a sheet of dough of a
uniform thickness and of a uniform quality is formed in a highly effective
manner.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a side view of a roller assembly of an embodiment of this
invention.
FIG. 2 is a schematic top view of the roller assembly of the embodiment.
FIG. 3 is a partial perspective view of the apparatus of the embodiment.
FIG. 4 is a partial top view of a first roller of the embodiment.
FIGS. 5, 6, and 7 are side views of roller assemblies used in conventional
stretchers.
FIG. 8 is a schematic diagram illustrating the loci of rollers used in this
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 an upstream conveyor 2 and a downstream conveyor 3 are disposed
in series. The upstream conveyor 2 receives from an upstream source an
indeterminate form of a continuous mass of dough 1. The upstream and
downstream conveyors are independently driven by their respective motors
(not shown), so that the downstream conveyor 3 is driven at a higher speed
than the upstream conveyor 2.
Three rollers 4, 4' and 5 are supported by a roller frame 6, which is in
turn slidably supported by the frame for the apparatus (not shown), so
that the frame 6 can reciprocate over a given distance 1.sub.1 in the
traveling direction of the conveyor.
The rollers 4, 4' are disposed above the conveyors, and are spaced apart
from the downstream conveyor 3 by a given distance D, so that they bridge
the conveyors, and their axes are perpendicular to the traveling direction
of the dough on the conveyors. The reciprocation of the frame 6 causes the
rollers 4, 4' to reciprocate over a given distance 1.sub.1 (FIG. 2) in the
traveling direction while rolling.
A roller 5 is disposed upstream of the rollers 4, 4'. The gap between the
conveyor and the roller 5 is the same as or a little larger than the gap D
between the conveyor 3 and the roller 4.
The roller 5 is oriented at right angles with the rollers 4, 4', its axis
being aligned with the traveling direction of the dough on the conveyors
and as shown in FIGS. 2 and 4. It reciprocates over a given distance
1.sub.2.
The roller 4 is mounted on a shaft 41. A sprocket 42 is mounted on the
shaft 41 and fixed thereto.
The sprocket 42 meshes with a chain 71 that is driven by a variable-speed
motor 7 so that it goes around two sprockets that are positioned spaced
apart from each other by a preset distance. The chain moves parallel to
the conveyors.
The shaft 41 is pivotally mounted on one end of a crank rod 81. The crank
rod 81 is driven by another variable-speed motor 8 so that the shaft 41 is
simultaneously rolled and reciprocated through the movement of the
sprocket 42 on the chain 71 and caused by the reciprocating crank motion
of the crank rod 81.
Hence, when the crank rod 81 is operated, the roller 4 can be rolled and
reciprocated by means of the operation of the sprocket 42, which is
reciprocated by the motor 8 through the crank rod 81 on the chain 71.
The rollers 4 and 4' are connected via a belt 43 so that the movement of
the roller 4 is transmitted to the other roller 4', and so that the latter
can roll and proceed back and forth in the same manner as the roller 4. By
means of the transmission ratio of the belt 43, the diameters of pulleys
attached to the rollers are adjustable so that the peripheral speed of the
upstream roller 4' is kept lower than that of the downstream roller 4.
In this embodiment the variable-speed motor 7 is adjusted such that the
speed of the movement of the chain 71 is the same as the speed of the
downstream conveyor 3. The roller 4 is reciprocated so that it moves
between the upstream and downstream conveyors 2, 3. By adjusting the
variable motor 7 and the transmission belt 43, the peripheral speed of the
roller 4' is forcedly kept higher than the speed of the upstream conveyor
2 and slower than the speed of progress at which it rolls over the
downstream conveyor 3 without causing substantially any friction with the
dough.
The shaft 51, on which the roller 5 is mounted, is supported at both ends
by the arms of a U-shaped slider 52. A pinion 53 is mounted on one end of
the shaft 51. A small-diameter pinion 54 is mounted on a wall of the
slider 52 so as to mesh with the pinion 54.
The pinion 54 engages a rack 55, which is fixed on the frame 6 in the
direction transverse to the conveyor.
The slider 52 is slidably mounted on two rods 56 that span the frame 6 in
the direction transverse to the axis of the shaft 51.
The roller 5 is driven by an independent power device, such as a rotary
actuator or a reversible motor (not shown), which is mounted on the shaft
51 to roll the roller 5. The roller 5 is made to reciprocate by means of
the pinions 53, 54, and the rack 55.
The moving speed of the roller 5 can be changed by a regulator 57 (FIG. 3).
In a first embodiment, as shown in FIG. 2, the rolling locus of the roller
5 is such that when the roller makes one reciprocating stroke in the
direction of the movement of the conveyors over the distance 1.sub.1, it
makes one-half of a reciprocating stroke in the transverse direction over
the distance 1.sub.2, so that the dough 1 being carried on the conveyor is
stretched by the roller moving along the locus formed by the combined
lengthwise and sidewise movements of the roller.
FIG. 8 shows nine combined loci that are formed. While the roller makes no
stroke, or makes one or two reciprocating strokes in the lengthwise
direction over the distance 1.sub.1, it makes a half, one and a half, or
two and a half reciprocating strokes in the transverse direction over the
distance 1.sub.2. The loci thus obtained are as shown in FIG. 8. If the
roller makes no stroke in the lengthwise direction while it makes a half
stroke in the transverse direction, the upper left locus will be given
produced. If the strokes in the transverse direction are increased to 1.5,
the upper middle locus will be given. If the transverse strokes are
increased to 2.5, the upper right locus will be given. If the roller makes
one stroke in the lengthwise direction over the distance 1.sub.1, while it
makes half a stroke transverse, the locus will be as shown in the second
block on the lefthand column.
In the embodiments of this invention the roller affects the surface of the
dough in various directions, so that dough having an inner texture of a
uniform quality, in any direction, can be obtained.
Further, the rollers 4, 4' of this invention stretch dough in the
downstream and upstream directions in such a manner that the thickness of
the dough can be adjusted.
Experiments to evaluate the effects of this invention for bread dough
showed that when a dough sheet 20 mm thick was stretched by the
conventional rollers shown in FIGS. 5, 6, and 7, each under similar
conditions, the resulting sheets of dough were 10, 5, and 5 mm thick,
respectively.
In contrast, under the same experimental conditions the apparatus of this
invention achieved a sheet of dough 2 mm thick. Namely, the reduction
ratio of the embodiment of this invention was 1:10, while that of the
conventional rollers was 1:4 or 1:2. This proves the remarkable advantage
of this invention.
The Effects of the Invention
As is explained above, by providing rollers that reciprocate in both the
direction of travel of dough and the transverse direction, the method and
apparatus of this invention can stretch dough in various directions so
that a sheet of a high quality dough with a uniform texture and thickness
can be obtained from a continuous mass of dough conveyed in an
indeterminate shape.
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